Add method for generating a unique ID, remove equals() methods.

bramble-api/src/main/java/org/briarproject/bramble/api/UniqueId.java

@@ -6,14 +6,14 @@ import javax.annotation.concurrent.ThreadSafe;
 
 @ThreadSafe
 @NotNullByDefault
-public abstract class UniqueId extends Bytes {
+public class UniqueId extends Bytes {
 
 	/**
 	 * The length of a unique identifier in bytes.
 	 */
 	public static final int LENGTH = 32;
 
-	protected UniqueId(byte[] id) {
+	public UniqueId(byte[] id) {
 		super(id);
 		if (id.length != LENGTH) throw new IllegalArgumentException();
 	}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContactId.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.api.contact;
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -17,9 +16,4 @@ public class PendingContactId extends UniqueId {
 	public PendingContactId(byte[] id) {
 		super(id);
 	}
-
-	@Override
-	public boolean equals(@Nullable Object o) {
-		return o instanceof PendingContactId && super.equals(o);
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoComponent.java

 package org.briarproject.bramble.api.crypto;
 
+import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.security.GeneralSecurityException;
@@ -10,6 +11,8 @@ import javax.annotation.Nullable;
 @NotNullByDefault
 public interface CryptoComponent {
 
+	UniqueId generateUniqueId();
+
 	SecretKey generateSecretKey();
 
 	SecureRandom getSecureRandom();

bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorId.java

@@ -21,9 +21,4 @@ public class AuthorId extends UniqueId {
 	public AuthorId(byte[] id) {
 		super(id);
 	}
-
-	@Override
-	public boolean equals(Object o) {
-		return o instanceof AuthorId && super.equals(o);
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/GroupId.java

@@ -20,9 +20,4 @@ public class GroupId extends UniqueId {
 	public GroupId(byte[] id) {
 		super(id);
 	}
-
-	@Override
-	public boolean equals(Object o) {
-		return o instanceof GroupId && super.equals(o);
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageId.java

@@ -27,9 +27,4 @@ public class MessageId extends UniqueId {
 	public MessageId(byte[] id) {
 		super(id);
 	}
-
-	@Override
-	public boolean equals(Object o) {
-		return o instanceof MessageId && super.equals(o);
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoComponentImpl.java

@@ -8,6 +8,7 @@ import org.bouncycastle.crypto.CryptoException;
 import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.crypto.digests.Blake2bDigest;
 import org.bouncycastle.crypto.digests.SHA3Digest;
+import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.crypto.AgreementPrivateKey;
 import org.briarproject.bramble.api.crypto.AgreementPublicKey;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
@@ -41,6 +42,7 @@ import javax.inject.Inject;
 
 import static java.lang.System.arraycopy;
 import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_AGREEMENT;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_SIGNATURE;
 import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_CIPHERTEXT;
@@ -54,7 +56,7 @@ import static org.briarproject.bramble.util.LogUtils.now;
 class CryptoComponentImpl implements CryptoComponent {
 
 	private static final Logger LOG =
-			Logger.getLogger(CryptoComponentImpl.class.getName());
+			getLogger(CryptoComponentImpl.class.getName());
 
 	private static final int SIGNATURE_KEY_PAIR_BITS = 256;
 	private static final int STORAGE_IV_BYTES = 24; // 196 bits
@@ -128,6 +130,13 @@ class CryptoComponentImpl implements CryptoComponent {
 		}
 	}
 
+	@Override
+	public UniqueId generateUniqueId() {
+		byte[] b = new byte[UniqueId.LENGTH];
+		secureRandom.nextBytes(b);
+		return new UniqueId(b);
+	}
+
 	@Override
 	public SecretKey generateSecretKey() {
 		byte[] b = new byte[SecretKey.LENGTH];

briar-api/src/main/java/org/briarproject/briar/api/client/SessionId.java

@@ -16,9 +16,4 @@ public class SessionId extends UniqueId {
 	public SessionId(byte[] id) {
 		super(id);
 	}
-
-	@Override
-	public boolean equals(Object o) {
-		return o instanceof SessionId && super.equals(o);
-	}
 }